The first F-35A stealth fighter aircraft for South Korea has made its public debut at a sensitive time for diplomacy on North Korea.

South Korea and the United States held a joint rollout ceremony for the jet at Lockheed Martin's assembly line in Fort Worth, Texas, on Wednesday (local time).

Defense officials said the production of the fifth-generation F-35A Lightning II jet for South Korea is significant in its combat readiness.

"Today is a truly meaningful day as we celebrate the rollout of the Republic of Korea (ROK) Air Force's first F-35A, the world's best fighter jet, which will secure the sovereign airspace of the ROK," South Korea's Defense Song Young-moo said in a video message. "The deployment of the F-35 will serve as momentum to enhance the combined operations of the ROK-U.S. Air Forces and advance ROK Air Force's support capabilities for ground operations."

On behalf of Song, Vice Defense Minister Suh Choo-suk attended the event, along with Lt. Gen. Lee Seong-yong, vice chief of staff of the nation's Air Force.

Also on hand was a group of U.S. defense officials, including Ellen Lord, under secretary of defense for acquisition and sustainment, and Vice Adm. Mat Winter, program executive officer for the F-35.

"This is a major step forward for our F-35 enterprise and our ROKAF partners as we deliver Korea's first F-35, the first of six F-35 aircraft that will be delivered this year," Winter said. "The F-35A is a game-changing capability that will enable the South Korean forces to operate side-by-side with our U.S. forces in protecting your nation's homeland."

It's the first of 40 F-35As South Korea has agreed to purchase in a 2014 contract.

Adding to the Air Force's existing fleet of F-15Ks and F-16s, the F-35As are expected to play a key role in the country's defense against North Korea's threats.

It's South Korea's first warplane with the capability of evading radar detection.

"Based on a superb stealth capability, it can also contribute greatly to deterrence by enabling a clandestine infiltration into a site anytime, anywhere and a selective strike," said DAPA, South Korea's state arms agency.

The F-35A jet will be used for the training of South Korean pilots and maintainers at Luke Air Force Base in Arizona before delivery to Cheongju Air Base in South Korea in the first half of 2019.

The 40 F-35As will be deployed to South Korea by 2021, added DAPA.

The debut of South Korea's maiden stealth fighter came amid brisk diplomacy that may fundamentally change regional security conditions.

The North's leader Kim Jong-un visited Beijing for a meeting with Chinese President Xi Jinping earlier this week.

Kim also plans to hold back-to-back summit talks with South Korean President Moon Jae-in and U.S. President Donald Trump in the coming months. (Yonhap)